Transfer device



Sept. 16, 1958 H. B. CHATFIELD TRANSFER DEVICE 4 Sheets-Sheet l FiledJune l5, 1954 .im Elli! I l lill:

- mmm Y Sept. 16, 1958 H. B. CHATFIELD TRANSFER DEVICE 4 Sheets-Sheet 2Filed June l5. 1954 llllllllllllllllllllll lli!) IIII Il H. B. CHATFIELDTRANSFER DEVICE Sept. 16, .1958 2,851,979

Filed June 15, 1954 4 Sheets-Sheet 3 124/25 @p53* /02 Lw /Z/ ATTORNEYSept. 16, '1958 H; B. cHATFlELD 2,851,979

TRANSFER DEVICE Filed June l5. 1954 v 4 Sheets-Sheet 4 INVENTOR HenriyB,Chatelql ATTORNE United States Patent O TRANSFER DEVICE Henry B.Chatield, Kinsman, Ohio Application June 15, 1954, Serial No. 436,880

` 3 Claims. (Cl. 113-38) The present invention relates to punchingapparatus and more particularly to gang dies and novel feeding mechanismfor advancing articles progressively along a row of dies and associatedpunches.

To progressively form a series of articles simultaneously, a long stripof sheet material may be fed past alined equally spaced dies inincrements equal to the distance between the dies so that a series ofpunching operations can be performed on each article before it isdetached from the strip. The use of such a method increases the rate ofproduction but involves a large waste of material and is thereforecostly. The present invention avoids this waste of material Withoutreducing the rate of production by feeding cut blanks to the first dieand then moving the partially formed articles simultaneously from die todie during intervals between punching operations.

The article feeding may be effected by means of a series of grippersmounted on a reciprocable carriage for movement therewith in timedrelation to operation of the punches, the grippers being adapted tocarry each article from a die to the next adjacent die while the punchesare retracted, to release the article, and to move with the carriagebackto the former `die before the next punching operation. The grippersare preferably mounted on opposite sides of the dies for movement towardand away from articles alined with the punches and dies when thecarriage is at opposite ends of its stroke.

Since each gripper must move into and out of the path of travel of thereciprocating punches and articles as it moves into and out of grippingposition and must grip an article for a substantial portion of eachoperating cycle, the speed of the punches and the frequency of thepunching operations must be limited Vto prevent the punches or thearticles moved thereby from striking the gripper. If the punchingmachine is provided with a long punching stroke and is operated at afrequency of less than twenty strokes per minute, it is relatively easyto move each gripper out of gripping position before the punches arelowered against the articles. However, if the stroke is shortened andthe frequency is increased, it is diicult to provide a reliable feedingmechanism which will operate satisfactorily for long periods of time.

According to the present invention the -grippers are moved into and outof gripping position extremely rapidly so as to permit reduction in thestroke of the punches and an increase in the frequency of the punchingoperations. The time required to move the -grippers into or out ofgripping position is preferably less than about one-fortieth the timerequired to move the punches into and out of the dies and to complete-one cycle of operations so that the articles being formed may begripped and released in the shortest period of time and at exactly theright instant. The machine of the present invention, due to the accurateand high speed operation of the grippers, can easily handle 50 or morearticles per minute and can operate satisfactorily when the frequency is2,851,979 Patented Sept. 16, 1958 greater than punching strokes perminute. Frequencies greater than strokes per minute are usuallyimpractical since the metal pieces being deformed not having beenannealed are apt to be torn or otherwise damaged and the punches are aptto be broken when the punches enter the dies at excessive speeds.

ln order to operate the gripping mechanism rapidly, the inertia andchange of momentum of the grippers and the actuating mechanism thereforare minimized. The articles are preferably gripped by relatively lightweight frangible gripping fingers mounted to reciprocate transversely ofthe gripper carriage. The fingers of the present invention arepreferably actuated by a relatively light weight frame or actuatingmember that is mounted for movement with respect to the grippercarriage. rPhe actuating member is moved in timed relation to operationof the punches and actuates all the gripping lingers simultaneously whenit is moved relative to the gripper carriage. However, it is preferableto provide a yieldable connection between the actuating member and eachgripping finger so as to avoid backlash and damage to the gripperactuating mechanism and to permit independent movement of the grippingfingers due to dierences in the sizes of the articles being gripped.

The change in momentum of the gripper actuating mechanism may beminimized by providing gripping fingers which have less inertia thanthat of the actuating member therefor and/or by providing between theactuating member and the gripping fingers a speed multiplyingconnection, such as a snap-action mechanism or suitable gears or levers.It is preferable to mount the actuating member for longitudinalreciprocation relative to the gripper carriage and to move the grippingfingers transversely on the carriage while the gripper carriage isstopped at the end of its stroke by means of levers or the like betweenthe ngers and the actuating member which reciprocate each grippingfinger through a greater distance than the length of stroke of theactuating member relative to the gripper carriage.

rl`he gripper carriage and the actuating member are moved by separateactuating means in timed relation to the operation of the punches, thegripper carriage being reciprocated in a direction parallel to the rowsof punches and dies and the actuating member being preferably movedrelative to said carriage while the carriage dwells in stationaryposition at opposite ends of its stroke. The actuating member ispreferably mounted on the carriage for longitudinal reciprocationtherewith and is preferably reciprocated longitudinally relative to thecarriage to actuate the gripping fingers. The carriage and the actuatingmember of the present invention are preferably moved by a pair of rotarycams which move the actuating member substantially in unison with thecarriage when the carriage is moved in either direction longitudinallyand which move the actuating member while the carriage is stationary ateach end of its stroke. The cam that moves the actuating member to causemovement of the grippers may be operably connected to the punches torotate through one revolution during each punching cycle and may beformed to move the grippers rapidly'into or out of gripping positionwhile the cam rotates through an angle of about 6 or 8 degrees. Bydesigning the cam inthis way it is possible during drawing of acup-shaped article for the gripping fingers to grip the cup until anadvancing punch starts to enter the cup and to `release the cup and moveout of the path of the punch and cup before the punch engages the bottomof the cup. Likewise the cup may be gripped while it is being strippedfrom the retracting punch and before the end of the punch leaves theinside of the cup.

By mounting the gripping lingers so that they are acy but are preferablyfrangible to prevent damage to the gripper carriage, the -gripperactuating mechanism, and other parts Yof the feeding .mechanism when apunch strikes a gripping finger or when the fingers grip a broken punchcaught in the stripper plate or in a die and attempt to advance `thesaine. A frangible connection is preferred between 'the gripperVcarriage actuating means and the gripping fingers so that the fingerscannot prevent move-7.

ment of the carriage actuating means.

Where a stationary stripper plate is provided to remove articles fromthe retractingpunches, there is danger that the gripping fingers willgrip a broken punch projecting' hrough the opening in the stripper platewhile the gripperv` carriage is being moved so as to effect a connectionbetween the gripper carriage actuating mechanism and thel frame whichsupports the stripper plate. To prevent damage to the machine, it ispreferable that this connection and/ or the connection between thegripping fingers and the carriage actuating mechanism be frangible, forexample, by providing frangible gripping fingers or other frangiblemembers. The gripping fingers may be made of a hard brittle metal sothat they will break before they prevent movement of the grippercarriage or otherwise damage the machine but will last for thousands ofpunching operations when the machine is operating properly. If desiredsuitable safety mechanism may be provided to *stop the machineautomatically when a punch or a finger breaks or when an article is notremoved from a die and properly gripped by the gripping fingers. By theuse of such safety devices and rigid frangible ingers which may beeasily .replaced when broken, extensive shut-downs 'are 'avoided and `ahigh production rate may be'maintained.

The rotary cams employed for reciprocating the gripper carriage and thegripper actuating memberare preferably of a type which may readily bemodified or replaced to vary the timing of the feeding mechanism withrespect to the punches, the distance the grippers are moved, and/or thespeed of movement of the grippers. It is preferable to provide camshaving face grooves -formed by cam members vwhich may be removed andreplaced or otherwise modified. The cam which operates the gripperactuating member is preferably provided with removable cam segmentswhich may -be replaced with segments of differentA shapes to vary theoperation of the gripping fingers.

An object of the present invention is to provide a vmachine which iscapable of performing a series of progressiveoperations on afseries ofarticles advanced therethrough such as drawing, coining, sizing,piercing, trimming, etc. and which is capable of performing theoperations automatically at maximum speed and with a minimum Aofymaterial so as to minimize the cost of the operations.

A further object of the invention is to provide a high speed feedingmechanism which accurately positions the articles with 4respect to thepunches and dies before each punching operation.

A still further object is to provide a high speed feeding mechanism thatreleases the articles being formed substantially simultaneously withmovement of the punches against the articles and that grips the articlessubstantially simultaneously with stripping of the articles from thepunches.

Another object of the invention is to provide a feeding device havinggripping mechanism of lowV inertia which "mayr'belreciprocatedatgeirtrernely high speeds.

A further object of the invention is to provide a high speed feedingmechanism for a punching machlne which is not permanently damaged byroutine failure of moving parts or improper forming of articles andwhich can manufacture a maximum number of pieces before extensiverepairs are required.

A still further object is to provide a high speed gripper actuatingmechanism whose timing or speed may be readily adjusted with respect tooperation of the punches.

Other objects, uses and advantages of the present invention will beapparent -fron'tihe following description and from the drawings inwhich: A n

Figure l is a front elevational view of a punching machine constructedin accordance with the present invention;

Figure 2 is a fragmentary vertical section on a larger scale with partsbroken away showing a portion of the punching machine including thedies, the stripper, and the gripping fingers, the articles being shownin solid lines in the positions in which they are gripped shortly afterthey are stripped from-the punches;

Figure 3 is a fragmentary top Vplan view of the machine on a differentscale with parts broken away, the grippers being shown in grippingposition;

Figure 4 is a fragmentary side elevational view of the feeding mechanismshown in Fig. 3 with parts broken away and shown in section;

Figure 5 is a fragmentary vertical section with parts broken away on alarger scale and showing portions of the blank feeding mechanism;

Figure 6 isa vertical sectional view with parts broken away takensubstantially on the line indicated at 6 6 1n Fig. 4 and on a largerscale;

Figure 7 is a vertical sectional view with parts broken away takensubstantially on the line indicated at 7 7 in Fig. 4 and on the Asamescale as Fig. 6 showlng how the gripper carriage 'and thefra'rn'eme'mber are connected to their actuating pistons; r

Figure 8 is a fragmentary verticalsectional View taken substantially onthe line indicated at 8-8 in Flg. 3 but on a larger scale and with partsbroken away; D

Figur`e'9 is a fragmentary vertical sectional v1ew taken substantiallyon-the line indicated at 9-9 in Flg. 3 but on a larger scale andwith'parts removed;

Figure 10 is a diagrammatic fragmentary plan v1ew on a reduced scale andwith parts broken away to illustrate the general operation of thegripper carriage and the frame member sliding therein;

Figure 'll is an elevational view on an enlarged scale of the cam andfollower actuating means for the carriage and the frame member when thecarriage is Yat one end of its stroke and an instant after the grippingfingers are retracted, the follower and a portion of the cam for thegripper carriage being shown in dotted'lines;

Figure l2 is an elevational viewsimilar to Figure ll but showingthe'cams in'fheir'po'stions'when the carriage is at`the opposite end ofits"strokeandan instant before the gripping lingers are advanced togripping position; and

Figure 13 is a fragmentary plan view showing details of the feedingmechanismisho'wn in Fig. 3 but on a larger scale and with parts brokenaway and shown in section,

' the position of the parts when the grippers are completely retractedbeing shown vin solid lines and the position of one gripping finger andthe lever 'connected thereto when an article is .gripped being shown indotted lines.

Referring more particularly to -the drawings in which like parts areidentified with the same numerals throughout the several views, Figure 1Vshows a progressive punching machine includingastationary upright frame1 having a lower base portionZ, an upper-head portion 3, and anintermediate portion including an elongated horizontal table 4 whichrests yon andprojects outwardly from the base vportion 2. The'tableprovides a rigid support for a row fof longitudinally-alignedequally-spaced dies to 1'1 which are held in fixed position with theirupper edges substantially in a single plane. The head portion 3 of theframe provides a rigid support for a iiywheel 12 and for a punch holder13 which carries a row of longitudinally alined equally spaced punchesto 21, each in axial alinement with one of said dies.

The flywheel 12 is mounted on a crankshaft 22 for continuous rotationon'the head 3, and the punch holder 13 is slidably mounted betweenopposed vertical ways 23 and 24 for reciprocation vertically toward andaway from the dies carried by the table 4. A motor or other suitabledriving means is provided to continuously drive the flywheel in onedirection, and a driving connection such as a crank and connecting rodor the like is provided to convert rotary motion of the flywheel intoreciprocation of the punch holder. As herein shown, the cranksl'iaft 22is journaled in the head 3 and has an integral crank pin or eccentricwhich is journaled in the upper end of an oscillating connecting rodwhose length is adjustable to vary the vertical position of the punchholder. The connecting rod 25 has a ball and socket connection 26 to thepunch holder 13 so as to permit oscillation of the connecting rod as itmoves the holder vertically.

By adjusting the length of the connecting rod 25, the distance that thepunches move into the die cavities can be closely controlled. The lengthof stroke of the punches is fixed as determined by the distance betweenthe axes of the crankshaft and the crank pin and is suiiicient to movethe punches out of the dies the distance required to permit feeding ofarticles from die to die. in the punching machine shown in the drawingsthe bottoms of the punches are elevated a distance above the top of thedies at least several times the maximum lheight of the articles beingformed so as to provide room from suitable gripping and strippingmechanism above the dies.

According to the present invention an individual blank is fed to thefirst die S during each rotation of the flywheel 12 and the articlesformed from the blanks are progressively advanced from die to die sothat a series of operations are performed on each article as it advancesfrom the first die 5 to the last die 11. Each time the punch holder ismoved by rotation of the iiywheel to its lowermost position and so longas the punching machine is full of pieces the following operations areperformed simultaneously:

(a) the punch 15 enters the die 5 and draws a cup from a circular blank,

(b) the punch 16 enters the die 6 and redraws a cup received from die 5.

(c) the punch 17 enters the die 7 and performs a second redrawingoperation on a cup,

(d) the punch 18 coins and sizes a cup shaped article in the die 8.

(e) the piercing punch 19 passes through a piercing ring in the bottomportion of the die 9 and cuts a circular slug from the article in saiddie.

(f) the punch 20 performs a chamfering `operation and further shapes thearticle in the die 10, and

(g) the trimming punch 21 passes through a trim ring forming the upperportion of the die 11 to cut excess material from the margin of thearticle and to eject the article downwardly through the die, theposition of the article at the instant of cutting being shown in dottedlines in Fig. 2.

The articles shown in solid lines in Fig. 2 are shown in the positionsthey have shortly after they are stripped off the punches and gripped,it being understood that the punches will move upwardlya substantialdistance from their position shown in Fig. 2 as the articles areadvanced by the grippers and before the holder 13 reaches the top of itsstroke. Before the punches are again lowered the articles are accuratelyadvanced a distance equal to that between the axes of adjacent dies. Theposition of the circular blank fed to the die 5 and the position of thearticle advanced from the die 1G to the die 11 before lowering of thepunches is shown in dotted lilies in Fig. 2.

Suitable discharge chutes are provided to remove slugs cut in the die 9and finished articles cut or trimmed in the die 11. As herein shown, thetable 4 is provided with inclined passages or chutes 27 and 28 leadingfrom the lower end of the dies 9 and 11, respectively, to the exteriorof the table. The positions of a slug and a iinished piece in the chutesare shown in dotted lines in Fig. 2. If desired an extension 29 may beprovided on the frame to convey the finished pieces from the chute 28 toboxes or other article containers.

According to the present invention the pieces formed in the dies arelifted a predetermined distance out of the dies after each punchingoperation and are then gripped and advanced before the next punchingoperation. Suitabe means is provided to remove each piece from the dieafter each punching operation. The punches and dies may be designed sothat the pieces cling to the punches as they are retracted and thepieces are pulled out of the die cavities by the punches. For example,each piece formed in the die 9 is removed therefrom by the punch 19.However it is preferable to provide suitable bottom ejectors below thedie cavities so as to insure that the pieces areV properly removed fromthe dies at all times.

As herein shown, each of the dies 5, 6, 7 and 8 is provided with anejector rod or plunger mounted on the table 4 for reciprocation alongthe axis of the die. The upper portions of the plungers 130 have adiameter substantially less than that of the die cavities and engage thebottoms of the cup-shaped articles formed in the dies. A similar ejectorrod or plunger 131 is provided for the die 1t) and is mounted like theplungers 130 coaxial with said die. The plunger 131 is the same as eachplunger 130 except that the upper portion thereof carries an -enlargedhead 132 which slides in the die 10 and has yan external diametergreater than the inside diameter of the sleeve-shaped article formed inthe die.

Each of the ejector plungers 130 and 131 is provided with a circularflange 133 and is biased toward the punches by an ejector spring 132.The article engaging face of each plunger 130 is preferably shaped toconform to the shape of the article being formed and as herein shown isfiat so as to resist tilting of the article as it is advanced into orejected from the die. The upward movement of the plunger 130 and 131 islimited by the iianges 133 as shown in Fig. 2, but the plungers are freeto move downwardly when engaged by an article being advanced into thedie. Since each ejector plunger engages an article when it iirst entersa die and aids in positioning the article as it is being deformed, eachplunger improves the accuracy of the forming operations. It will beunderstood that each plunger is accurately guided for reciprocation insuitable bores so that tilting of the plungers is avoided.

Suitable stripping means is provided to remove the pieces from thepunches after they have been raised a predetermined distance above thedies and suitable grippers are provided to grip the pieces substantiallysimultaneously with stripping of the same from said punches. The piecesmay be stripped at the proper time by stripping means carried by thepunches or by the grippers but it is preferable to mount the stripperson the stationary frame independently of the grippers and punches.

As herein shown, a horizontal stripper plate 30 is mounted on the table4 and has a stationary position a iixed distance above the dies at theinstant it is engaged by the pieces being raised by the punches. Thisstripper plate has a row of longitudinally alined equally spacedcircular openings, each coaxial with a punch and die. Each opening has adiameter greater than the maximum diameter of the punch and smaller thanthe maximum diameter of the piece formed by said punch so as to permitadvancing of the punch into the die and to strip pieces from the punchas the latter is retracted. The stripper plate 30 is shown herein asbeing stationary, but

aan 1,979

-it may be mounted formovement downwardly when the punches Jare loweredso longas itstrips the pieces from -thepunches substantially `as shownin Fig. 2.

The stripper plate is :also shown in position above `the die 11 toinsure removal from the punch of any scrap VVring which maybe formedduring trimming. However, this -portion of the stripper plate may beomitted and Qreplaced by-a spring-pressed stripper sleeve mounted on-the punch 21 since the scrap ring may be stripped from `the punch atany time.

-driven in timed relation tothe operation of the punches to 21 so as toadvance a separate -blank to the first die 5 and to advance Veach piecefrom one die to the next adjacent die while thepunches are retracted.The

`pieces are advanced by light weight gripping fingers 31 and the blanksare advanced by a feed plate 32 in timed .relation to the rotation ofthe flywheel 12 and reciprocation of the punch holder 13. The feedingmechanism 4for controlling the grippingngers and the blank feed plate isdriven from the crankshaft 22 by any suitable means, such as a sprocketand chain or suitable gearing. As herein shown, a sprocket wheel 33fixed to the crankshaft .'22 is drivingly connected to a sprocket wheel34 and an idler sprocket 35 by means of a link chain 36, the wheel 34rotating once each time the crankshaft makes one revolution.

The sprocket wheel 34 is keyed to one end of the shaft 371so that theshaft is driven at a speed fixed with respect to the speed of rotationof the iiywheel 12. The shaft is journaled in a `stationary housing 38carried by the table 4, said housing being rectangular in vertical crosssection and having longitudinal side walls 39 and 40, a horizontalbottom wall 41, and a removable horizontal cover 42. The shaft 37 iscarried by ball bearings 43 and 44 in the walls 39 and 4t),respectively, for rotation about a transverse axis preferably parallelto the horizontal axis of the crankshaft 22 and normal to thelongitudinal rows of punches and dies.

The outer end of the shaft 37 is keyed to an externally cylindricaleccentric disc 45 to drive the same. An eccentric rod 46 has aninternally cylindrical ring portion .47 rotatably mounted on said discfor oscillation thereon. Since the ringV portion 47 is eccentricand notconcentric to the shaft 37, rotary movement of the shaft causes.reciprocation of the rod 46 and oscillation of a lever 48 that ispivotally connected at its lower end to the end of the eccentric rod 46.The lever 48 is drivingly connected to a lever 49 by means of arotatably mounted pivot pin or shaft 50 that is keyed or otherwiseconnected to the levers for oscillation therewith about a fixed axis.The shaft 50 is rotatably supported from the table 4 by a bearing member51 which is bolted to the underside of the table 4.

The upper end of the lever 49 is pivotally connected to one end of ayieldable connecting rod 52 by means of a yoke 53 and a pivot pin 54.The opposite end of the connecting rod is pivotally connected lin asimilar manner to the upper end of a lever 55 which is rotatably mountedonthe table 4 for oscillation with the lever 49. The lever 55 isdrivingly connected to a toothed gear segment '56 by means of atransverse pivot pin or shaft 57 which is keyed to said lever and saidsegment and is rotatably mounted to oscillate therewith about a fixedaxis parallel to the shaft 37. The shaft '57 is rotatably supported onopposite sides of the segmental gear 56 by bearings 58 and 59.

An arm 60 is rigidly connected to the shaft 57 for oscillation therewithin unison and has an outer end extending below the table 4. The arm isdrilled and threaded to receive an adjusting screw 61 which projects-opposite sides of the feed plate 32.

'from the outer end of the arm toward the bottom of the table and servesas an adjustable stop to limit oscillation of the segment 56 in onedirection.

Slidably mounted on top of the table 4'is a flat rack member 62 rigidlyconnected to the feed plate 32 and having teeth meshing with the teethof the gear segment 56 to convert oscillating movement of the shaft 57into longitudinal reciprocation of the feed plate. The rack 62 is shownin its fullyretracted position in Fig. 5 and obviously cannot beadvanced a distance greater than .that between its forward edge 63 andan upright edge 64 of the table. However, the screw 61 is preferably so`adjusted that the head thereof engages the bottom of the table 4 andprevents engagement of the edges 63 vand 64.

vSince movement of the lever 49 counterclockwise moves the adjustablestop 61 against the table ras shown in Fig. 4, the connection betweenthe lever 49 and the lever 55 is preferably yieldable to permit movementof the lever 49 a short distance counterclockwise after the segmentalgear 56 is stopped by the screw 61. AS herein shown the connecting rod52 includes a hollow tubular portion 65 which has a long cylindricalrecess containing a long compression spring 66 and a long slender rod 67inside said spring. The rod 67 is rigidly connected at one end to areduced plunger portion 68 of the yoke 53 and has an enlarged head 69 atits opposite end that engages the spring 66 to compress the same whenthe yoke S3 is moved away from the tubular portion 65 which is connectedto the lever 55. The tubular portion of the connecting rod is rigidlyconnected to an annular guide 70 which has an internal bore providing acylinder for slidingly receiving and guiding the plunger portion 68.Movement of the lever 49 clockwise as viewed in Fig. 44 moves theenlarged portion of the yoke 53 against the end of the guide 70 andpositively drives the connecting rod and the rack in a direction toretract the feed plate 32. Movement of the lever 49 in the oppositedirection compresses the spring 66 between the head 69 and the end ofthe guide 70 and yieldingly advances the feed plate. The spring will becompressed to permit sliding of the yoke 53 with respect to the tubularportion 65 when the screw 61 engages the table 4.

As herein shown the feed plate 32 is adapted to feed Vflat sheet metalcircular blanks 6 of a given size to the rst die 5. The blanks areguided to a position to be engaged by the feed plate by means of amagazine 71 having a plurality of upright guide rods 72. The magazine isheld in upright position on the table 4 by an annular marginal flange 73which is connected to the table on The flange is spaced from the portionof the table top over which the feed plate and the blanks slide adistance greater than the thickness of a blank and greater than thethickness of the feed plate as shown in Fig. 5 so that blanks may slidehorizontally from beneath the magazine 71 toward the first die 5.However, this distance is preferably less than twice the height of ablank to prevent more than one blank from being fed from the stack atany one time.

The feed plate 32 has a thickness less than that of each circular blank6 and when advanced by the rack 62 removes the blank at the bottom ofthe pile of blanks from the pile and advances it toward the die 5. Thebottom portion of the magazine 71 prevents any other blanks in the stackfrom being advanced at this time. The stop 61 may be adjusted so thatthe feed plate 32 advances a blank a distance equal to or slightlygreater than the diameter of the blank each time the flywheel 12 rotatesone revolution. When the blanks reach the die 5 they may be guided intothe proper position coaxial With the die. As herein shown a stop 14 isprovided to halt each blank at the proper place before it is drawn intoa cup, the position of a blank just before drawing thereof being shownin dotted lines in Figs. 2 and 5 coaxial with the die 5. If the normalstroke of the feed plate 32 is too great due to improper adjustment ofthe stop 61, the stop 14 will 9 prevent advancing of the blanks beyondthe end of the die and will cause the spring 66 to compress so as toreduce the stroke of said feed plate.

The spring 66 not only permits adjusting the stroke of the feed platebut also avoids damage to the machine where the blanks jam duringfeeding or where a broken punch and/ or a drawn piece remains in the die5 to prevent advancing of the feed plate.

The novel feeding mechanism of the present invention includes acylindrical vcam wheel 74 that is keyed to the shaft 37 for rotationtherewith. Opposite sides of the Wheel are provided with endless facegrooves 75 and 76, each of uniform depth throughout its length. Thegrooves provide two non-circular guides of somewhat similar shape forreceiving two cylindrical follower rollers 77 and 78 which, in thepunching machine shown herein are substantially coaxial when thegripping iingers are in gripping position, the diameter of each followerbeing substantially equal to the width of its associated cam groove. Thefollower rollers are rotatably mounted on parallel stub shafts 79 and 80which are carried by levers 81 and 82 for oscillation therewith. Thelevers are located adjacent opposite faces of the cam wheel 74 and arerigidly connected at their lower ends to a pair of coaxial pivot pins orshafts 83 and 84. Said pivot pins are journaled in a pair of bearingbosses 85 and 86 carried by the side walls 39 and 40 of the housing 38and are mounted to oscillate with the levers 81 and 82 about an axisparallel to that of the shaft 37.

The levers 81 and 82 are operatively connected to cylindrical push rods87 and 88, respectively, which are slidably mounted in the housing 38 toreciprocate horizontally along two xed parallel axes parallel to therows of dies and punches. The rods are mounted to slide in guide blocksS9 and 90 carried by opposite end walls of the housing 38 and areprovided with enlarged rectangular portions 91 and 92 intermediate theguide blocks. The enlarged portions of the rods have fiat verticalsurfaces in sliding engagement and are slotted to receive the upper endsof the levers 81 and 82 and a pair of anti-friction rollers 93 and 94,the width of each slot being substantially the same as the thicknessesof the roller and the lever in said slot. The roller 93 is mounted inthe portion 91 for rotation on a stub shaft 9S carried by said portion.The roller 94 is similarly mounted on a stub shaft 96 carried by theportion 92 for rotation about an axis parallel to the axes of the shafts37 and 95. The upper ends of the levers 81 and 82 are provided withvertically elongated slots 97 and 98 of a size to receive the rollers 93and 94. The slots preferably have a width substantially equal to theexternal diameter of said rollers so that lost motion between the pushrods 87 and 88 and the levers 81 and 82 is less than about 0.001 inchwhen the rods are reciprocated due to rotation of the cam wheel 74.

The ends of the push rods are externally threaded and are received byinternally threaded connecting blocks 99 and 100 of rectangular crosssection. The blocks are slotted to receive dovetails 101 and 102 whichare internally threaded to receive spaced pairs of transversely alinedupright attaching bolts 103 and 104. The Shanks of the bolts 103 and theupper portion of the dovetail 101 are received by a separate rectangularblock 105 whereas the shanks of the bolts 104 and the upper portion ofthe dovetail 102 are received by a transverse cross-bar 106.

The push rods S7 and 88 are rigidly connected to a gripper carriage 107and an actuating frame member 108, respectively, to reciprocate the samein timed relation to the `operation of the punches. The gripping fingers31 are moved into and out of a gripping position in response to relativemovement between said carriage and said frame member and are likewisemoved in timed relation to operation of the punches.

The gripper carriage and the frame member are mounted -on the frame 1for sliding movements parallel to the rows of punches and dies. Asherein shown, the table 4 l10 has upwardly projecting guide portions 109and 110 which extend longitudinally and form with the upper surface ofthe table a groove or nay of rectangularV cross section for slidablyreceiving the frame member and the gripper carriage.

The frame member or actuating member 10S comprises a pair `oftransversely-alined longitudinally-extending actuating bars 111 and 112which are rigidly connected by a pair of cross-bars 106 and 113. Thecross-bar 106 is rigidly connected to the connecting block and the pushrod 08 by the dovetail 102 and the bolts 104 so that the frame member108 reciprocates in unison with the push rod 88. The outer side faces ofthe bars 111 and 112 are parallel and slidably engage the inner faces ofthe guide portions 109 and 110, respectively. The bottoms of the barsare located in a horizontal plane and slide on the iiat upper surface ofthe table 4 in a direction parallel to the rows of punches and dies asguided by the portions 109 and 110.

The gripper carriage 107 includes a large fiat upper plate 114 whichextends horizontally from one end of the guide portions 109 and 110 tothe connecting block 99 at the opposite end of said guide portions. Theplate extends between the portions 109 and 110 and has marginal portionswhich slide horizontally in longitudinal grooves or ways 115 and 116 ofuniform depth and height formed in said portions. The plate has a narrowlaterally elongated slot 117 of a width to receive the bolts 103 and isrigidly secured by said bolts to the connecting block 99 and the pushrod 87 for reciprocation therewith.

Rearwardly of the guide portions 109 and 110 the table 4 has parallelguide portions 118 and 119 with longitudinal grooves similar to the ways115 and 116 for slidably receiving marginal portions of the rack 62 toguide the same in a longitudinal direction parallel to the rows ofpunches and dies.

Six pairs of rigid gripping fingers 31 are carried by the carriage 107between the stripper plate and the seven dies, and a longitudinallyelongated slot 120 is provided in the upper plate 114 to permitreciprocation of the carriage without interfering with lowering of thepunches into the dies. As herein shown, the slot has a width to exposethe gripping iingers when they are advanced or fully retracted. The six-gripping fingers on each side of the slot are carried by a pair ofsuperposed longitudinal members 121 and 122 which are rigidly connectedby suitable bolts or the like. Each pair of these members is ofsubstantially rectangular cross section, has flat bottom surfacesslidably engaging the flat upper surface of the table, and has liatouter surfaces slidably engaging one of the bars 111 and 112. The fiatbottom of the plate 114 engages the flat upper surfaces of the twomembers 121 and slidably engages the flat upper surfaces of theactuating bars 111 and 112 `of the frame member 108 to prevent movementof said members away from the table 4.

The pairs of superposed members have inner edges substantially flushwith the sides of the slot 120 and are rigidly connected to the plate114 for movement therewith in unison. As herein shown this rigidconnection is effected by a plurality of equally spaced dowel-like pivotins 123 which extend through circular openings in the plate 114 and inthe superposed members 121 and 122.

In the device shown herein, the superposed members carry six .equallyspaced pairs of laterally alined pistonlike gripper carriers 124 whichare mounted for reciprocation on the gripper carriage 107 in a directionnormal to the -direction in which the carriage is reciprocated. Afrangible wire gripping linger 31 is detachably connected to eachcarrier 124 by a screw 125, the piston being bifurcated to receive thewire ends of the linger as is best shown in Fig. 9. The six equallyspaced pairs of gripping fingers are automatically moved transversely inresponse to relative longitudinal movement between the actuating bars111 and 112 and the gripper carriage 107. The fingers of each pair ofgrippers are alined laterally and are fmovable towards each .other togripping position when ja 1piece .istodne `advanced from one dietoanother.

LIt will be .understood that any suitable grippers may be employed inthe punching machine and that articles of various shapes and sizes maybe handled. As herein shown, the fingers are adapted to grip cup-shapedpieces of the .typeshownin Fig. 2, and each finger 31.is formed from `asingle lpiece offrangible hardened steel wire and is bent so that thewireends are horizontal and-the intermediate .portion is U.shaped andupright. The legs of the U-shapedportion are vertical and providearticle engaging surfacesgfor gripping the pieces formed by the punches.,The top part ofY said U-shaped portion is bent inwardlyas best shown inPigs. 8 and-9 toy provide clearance for the vround portion `of the.article'projecting between the articlegripping legs.

.The1carriersl24 and the ngers 31.are moved'into and out Yof .grippingpositionby a plurality .of Ybell cranks or levers 126, each of which ismounted on one of the pivot pins 123 toconvert longitudinal movement ofthe frame member .108 on the carriage 107 into transverse movement of acarrier 124. The actuating bars 111 and 112 and the carriers 124 areprovided with slots to receive opposite ends of the bell cranks, saidends being rounded substantially as shown in Fig. 13 to facilitateoscillation of the cranks. The width of the slot in each carrier 124 ispreferably substantially the .same as the diameter of the rounded end ofthe bell crank Vreceived in said slot so as to eliminate lost motionbetween the bell crank and the carrier. However, the slots in .the bars111 and 112 are preferably large enough vso that the slots do notprevent Voscillationof the bell cranks to their retracted positions. Asherein shown, opposite end portions .of the bell cranks have a uniformthicknesssubstantially equal to the height of the slots in which theyoscillate.

In order to yieldably resist movement of the bell cranks .and thegrippers away from gripping position, the bars 111 and 112 are providedwithcoaxial cylindrical bores for slidably receiving a .plurality ofpiston-like followers 127 :as best shown in Fig. 13. Each follower isheld .against the rounded end .of a bell crank or lever 126 by acompressionspring 128. Theend of each bell crank is normally heldagainst the upright wall of its slot by the spring and is normally movedby one of the actuating bars 111 and 112 into and out of grippingposition. However, `the spring is .arranged to permit yielding of thegripping fingers radially when the article being gripped preventsmovement of the ingers radially inwardly whereby crushing of the articleor damage to the gripping fingers is avoided. The followers 127 and thefollower springs 128 thcreforerprovide a resiliently yieldableconnection between the frame member 108 and each of the gripping fingers31.

According to the present invention the inertia and change of momentum ofthe grippers and the vgripper actuating mechanism are minimized so as topermit operation at extremely highspeed. The frame member 108 and thefollowers 127 carried thereby are of relatively light weight and havelittle inertia resisting linear acceleration. Similarly the bell cranksor levers are relatively light and have little'resistance to angularacceleration. The gripper carriers 124 and the gripping fingers 31carried thereby are extremely light and have even less inertia than theframe member 108. In order to minimize the change in momentum when thegrippers are actuated it is preferable to provide a speed multiplyingconnection between the frame Vmember and each gripping finger so thatmovement of the frame member is minimized. As herein shown the leversV126 provide speed multiplying connections between theframe member andthe carriers 124. The pivot pins 123 are located -closei' to the ends ofthe levers 126 which engage the frame member than to the ends l-of thelevers which engage the carriers '124 so thatthe-carriers andthe-grip--ping fingers supported thereby move atleast 50% Vfarther withgrespectto ,the `gripper'carriage than. the-framemember.

Each carrier 124 is .accuratelyguidedinits .associated bore;and.rigidly.supports a gripping finger V31-so that the finger is ,accurately.positioned with respect to .the punches :and dies ywhen it moves .into.gripping posi tion. Each .gripping .finger .must be vsubstantiallyrigid and sufficiently strong to .accurately position .articles in.alinement with the punches and dies and yet must be frangible toprevent damage to .the .machine .whenexcesforces are appliedtothelingers. A rigidfinger is preferred since itmay be brittle .andsince. it permits positioning of the article gripped within .a fewthousandths of .aninch of thef desired location. In the machineshownherein the wire fingers 31 are rigid and .are vaccurately guided by thecarriers 124 .and .the gripper carriage is accurately controlled so.that articles are positioned within two or .three thousandths of aninchoi the desired lo-cation'when the machine is in operation.

fn order to prevent .damage lto the machine the ngers 31 are preferably.formed of hard brittle steel which 1s sufficiently .durable when themachine is functioning Yproperly but which is frangible when subjectedto excessive forces which might damage the gripper carriers, the gripperactuating mechanism, or the carriage actuating mechanism.

If the fingers grip a broken punch that is held against movement by thestripper plate 30 or by one of the dies, the fingers will break andcannot damage the machine by preventing reciprocation of the grippercarriage. lf a fingerdoes break, it can be readily removed by looseninga screw125 and replaced with another linger.

.The springs 123 cushionimpact ofthe .gripping fingers with the articlebeing gripped and prevent damage to the frangible fingers due toengagement of the fingers with tilted or oversize pieces.

The gripper carriage 107 and the frame member 103 are moved to opposite.ends of their strokes substantially in unison and are accuratelycontrolled by the cam wheel 74. .T he face grooves 75 and 76 may be cutor otherwise formed in opposite faces of the cam wheel but arepreferably formed by replaceable cam members so that the shape of thegrooves may be readily modified. In the event the length of stroke ofthepunches isxnodified by replacing the crankshaft 22, the type of punchesand dies is modified, or other changes are made, the shape of the camgrooves and the timing of the feeding mechanism may be readily varied.

As herein shown the cam wheel 74 is provided with annular grooves orrecesses and 136 in its opposite faces that are concentric to the shaft37 and which receive innerand outer cam members-to form the inner andouter margins of the cam grooves 75 and 76. The radiallyouter portion ofthe recess 136 receives -a plurality of segments 137 to 140 which abutto provide an endless cam surface that forms the outer margin of thegroove 76, and the inner portion of said recess receives a plurality ofsegments 141 to 144 that abut to provide an endless cam surface thatforms the inner margin of said groove.

The radially inner and outer portions of the recess 13S likewise receiveremovable cam members 146 and 147 which form the outer and innermargins, respectively, of the groove 75. Both the cam segments 13'7 toMd and the cam members 146 and 147 `are drilled and threaded to receivethe attaching bolts 145 and have fiat bottom surfaces and rounded outersurfaces which are held in engagement with the bottom andmarginal-surfaces of the annular grooves or recesses 135 and 136. Thesecam members and cam segments therefore form withthe cam wheel 7 a rigiddouble faced cam for actuating both the gripper carriage 107 and theactuating frame member 108 in a longitudinal direction. The cam membersform- The face grooves 75 and 76 formed on opposite sides of the camwheel 74 have a width and depth throughout their length to receive thefollower rollers 77 and '78 and are similarly contoured as best shown inFigs. ll and 12 so that the frame member moves substantially in unisonwith the gripper carriage when the gripper carriage is moved and movessubstantially the same distance longitudinally as said carriage. Theface groove 75 is smoothly curved throughout its length and reciprocatesthe gripper carriage without undue accelerations through a distanceequal to the distance between the axes of adjacent punches or dies.Opposite end portions of the groove 75 are of circular form so that thegripper carriage dwells in a stationary position for a substantialperiod of time at each end of its stroke. The groove 76 is shaped toprovide a similar reciprocation and a similar dwell for the frame member108 but has sharply curved projecting shoulders for rapidly moving theframe member while the gripper carriage is stationary at each end of itsstroke.

Operation of the cams will be apparent from Figs. l1 and 12. The camsegments 137 and 141 are radially alined and extend for about 180 toform half of the `cam groove 76. This half of the groove is identicalwith half of the groove 75 and is alined with said grooves so that theframe member moves in unison with the gripper carriage for about 180 ofrotation of the cam wheel 74. The groove 75 is symmetrical and moves thegripper carriage from one end of its stroke to another in about 60 ofrotation with a dwell of about 120 between actuations.

The abutting edges of the three segments 138, 139 and 140 are radiallyalined with those of the segments 142, 143 and 144, respectively, andeach segment preferably extends from 50 to 60 around the cam groove 76.As herein shown the segments 138, 140, 142 and 144 are of substantiallythe same angular extent and the segments 139 and 143 extend through anangle of about 65 The latter segments are smoothly curved throughouttheir length and have substantially the same curvature as correspondingportions of the cam members 146 and 147 so that the frame member and thegripper carriage move substantially in unison from one end of theirstroke to the other as the follower roller 78 is moved relative to thecam wheel from one end of the `cam segment 143 to the other.

As shown in Figs. l1 and 12, the symmetrical face groove 75 formed bythe cam members 146 and 147, half of which may be exactly the same sizeas the groove formed by segments 137 and 141, has a width throughout itslength substantially equal to the external diameter of its associatedfollower roller 77 so as to accurately control the position of thegripper carriage at all times. The portion of the face groove 76 formedby the cam segments 139 and 143 likewise has a width throughout itslength substantially equal to the diameter of the follower roller 78 soas to accurately control the position of the frame member 108. In orderto position the gripper carriage within .001 or .002 inch of the desiredlocation at each end of its stroke, the gripper actuating mechanismincluding the elements 83, 76, 97, 146 and 147 are preferably veryaccurately machined. If desired, the actuating mechanism for thegripping lingers 31 may also be machined with extreme accuracy so thatmovements of the fingers transversely are controlled within a fewthousandths of an inch.

lt will be apparent from Figs. 11 and 12 that the smoothly curvedfollower engaging surfaces of the cam segments 139 and 143 are parallelto and offset radially outwardly from the corresponding surfaces of thecam members 146 and 147 a predetermined distance equal to the length ofstroke of the follower roller 77 and proportional to the stroke of theframe member S so that there is no relative movement between the framemember and the gripper carriage except while the follower roller engagesthe cam segment 140 or 142.

The major follower engaging portion of the cam seg- 14 ment 142 iscircular and has the same curvature as the corresponding portion of thecam 147 with which it is alined so that the frame member may dwell withthe gripper carriage in a stationary position at one end of its stroke,but said segment is provided with a raised portion or shoulder 148adjacent one end of the segment 143 for rapidly actuating the framemember to cause moving of the gripping lingers out of gripping position.Also, the major follower engaging portion of the cam segment is circularand concentric to or parallel to the corresponding circular portion ofthe cam 146 with which it is alined so that the frame member may dwellwith the gripper carriage at the opposite end of its stroke while thegripping lingers are released. The cam segment 140 has a raised portionor shoulder 149 adjacent the end of the cam segment 137 for rapidlymoving the follower roller 7S to actuate the frame member 1118 and toadvance the fingers 31 to gripping position.

The follower engaging surface of the cam segment B between the shoulder149 and the segment 139 is concentric to the corresponding surface ofthe cam member 146 and tangent to the adjacent follower engaging surfaceof the segment 139 so that the actuating frame member 103 is not movedby the segment 140 until the follower roller 78 engages the shoulder149. The position of the cam wheel 74 an instant before the followerroller '78 engages the shoulder 149 is shown in Fig. 12, the grippingfingers being fully retracted at this time and out of gripping position.When the cam wheel rotates counterclockwise from its position shown inFig. 12, the frame member 108 and the gripping fingers are movedthroughout the full length of their gripping stroke While the cam wheelrotates through a small angle until the follower roller 73 engages thecam segments 137 and 141.

The follower engaging surface of the cam segment 142 between theshoulder 14S and the cam segment 141 is circular and coaxial with thecorresponding surface of the .cam member 147 with which it is alined andis tangent to the adjacent follower engaging surface of the segment 141sothat the frame member 103 is not moved by the segment 142 until thefollower roller 78 engages the shoulder 14S.

The curved follower engaging surfaces of the shoulders 143 and 149 arepreferably very steep so that the gripping lingers release the articlesand move out of the path of movement of the punches and articlessubstantially simultaneously with engagement of the punches with thearticles and so that the gripping fingers move to gripping positionsubstantially simultaneously with stripping of the articles from thepunches by the stripper plate 30. Each of the shoulders is preferablyformed to move the gripping iingers into or out of gripping position ina period of time less than about one-fortieth the time required for onerevolution of the flywheel 12 or for one punching cycle. As hereinshown, each of the shoulders 14S and 149 is at the end of its camsegment and extends circumferentially less than 10 around the margin ofthe cam groove 76 so as to move the follower roller 78 radially towardor away from a position in axial alinement with the roller 77 and tomove the lingers 31 at high speed into or out of gripping position whilethe cam wheel 74 rotates through an angle of about 6 to 8. The lingersare therefore moved the full distance from one end of their stroke tothe other while the flywheel 12 revolves through an angle of about 6 to8 and while the gripper carriage dwells in stationary position at oneend of its stroke.

By replacing the cam segments 140 and 142 with similar segments havingshoulders located at various angular positions, the timing of thegripper actuations with respect to the operation of the punches may beclosely controlled. The gripper lingers may be moved into or out ofgripping position in the path of movement of the punches in any desired6 to 8 of rotation while the follower roller engages the cam segments140 .or 142, and the shoulders 14S and 149 may be in any desiredposition. If the speed of the punching operations is increased ordecreased the angular extent and/ or slope of the shoulders may bevaried accordingly.

As herein shown, the shoulder 148 is positioned to initiate movement ofthe fingers 31 out of gripping position when the advancing punches passthrough the stripping plate 30 and begin to enter the cup-shapedarticles, and the curved surface of the shoulder is steep enough to movethe fingers out of the path of travel of the punches and the articlesbefore the bottom faces of the punches engage the bottom portions of thecup-shaped articles. Similarly, the shoulder 149 is positioned toinitiate movement of the gripping fingers ybefore articles are strippedfrom the punches so that the fingers are out of the path of travel ofthe punches and articles at the instant the articles engage the stripperplate 30 and are moved into gripping position in engagement with thearticles substantially at the instant the punches leave the upper endsof the articles. Since the gripping fingers and the gripper actuatingmeans are very light in weight, they ca'n move at extremely high speedand can grip the articles before said articles fall a substantialdistance away from the stripper plate 30. The high speed gripping andreleasing of the articles insures accurate positioning thereof in axialalinement with the punches each time the punches are lowered. A machineof the type shown can maintain accuracy of positioning within about .002or .003 inch. This is usually sufficient for high speed operation sincethe noses of the punches serve as guides to correct any slightmisalinement as the articles are moved into the dies. The ejector rods130 and 131 also help to correct misalinement as the articles areadvanced into the dies and to prevent misalinement as the articles areremoved from the dies.

The stripper plate 30 likewise aids in positioning the articles so as toprevent tilting of'the articles before they are gripped by the fingers31. The stripper plate is rigidly supported in a horizontal stationaryposition a predetermined distance above the dies greater than the heightof the articles being formed by lateral bars 150 and 151 which arerigidly connected to the portions 169 and 110 of the table 4 beyond theends of the row of dies. The bars form a rigid bridge for supporting thestripper plate in a predetermined position. The article engaging bottomsurfaces of the stripper plate surrounding each punch receiving openingare flat and perpendicular to the axis of the punch so that the articlesdo not tilt as they are stripped from the punches and gripped by thefingers 31. When the gripping fingers are in gripping position as shownin Fig. 8, the at bottom surfaces of the stripper plate 30 are only ashort distance above the top of the fingers so that there is littlechance for tilting or misalinement of the articles being gripped.

The cam surfaces of the segments 138 and 144 are l l formed so as topermit the desired movement of the roller 78 by the shoulders 148 and149 but need not e11- gage the follower roller for any substantialperiod of time while it is being controlled by the cam surfaces of thesegments 140 and 142. The cam surface of the segment 138 adjacent thesegment 139 is tangent to the cam surface of that segment, and the camsurface of the segment 144 adjacent the segment 141 is tangent to thecam surface of the latter segment.

As herein shown, the cam segment 138 is similar to the segment 140 andis provided adjacent the segment 137 with a sharply curved shoulder 150similar to the shoulder 149. The cam surface of the segment 138 betweenthe shoulder 150 and the segmentV 139 is circular and concentric to thecorresponding surface of the cam member 146. Such a construction ispreferred so that it is unnecessary to replace the segment 138 when thesegment 142 is replaced with a segment having its shoulder 148 closer tothe segment 141.

The cam segmentv 144 shown herein is similar to the r16 .segment .142vand is provided adjacent the segment 143 with a sharply Vcurved shoulder151 similar to the shoulder 148. The cam surface of the ,segment 144between the shoulder 151 and the segment 141 is circular Aand has thesame curvature as the corresponding surface of the cam member 147 withwhich it is alined so that itis unnecessary to replace the segment 144when the segment is replaced with asegrnent having its shoulder .149closer to the segment 139.

With thecam segments shown in the drawing the-timing of the gripperactuations withrespect to operation ofthe punches is normally adjustedmerely by replacing one `or both of the Acam .segments 140 and 142. Ifthe height of the stripper Vplate above the dies, the speed of themachine, or other thngsare changed, the timing of the gripper actuationsor the speed thereof may be readily changed by changing the angularposition or shape of the shoulders 148`and 149.

The feeding mechanism of the present invention operates at high speed inaccurately timed relation to the operation of the punches. In thepunching machine shown herein, each cycle of operation is substantiallyas follows:

(l) When the flywheel 12 is at top dead center and the punches are fullyretracted, the gripper carriage is in advanced position and the fingers31 are in gripping position above the dies 6 to 11, each pair of fingersholding an article in axial alinement with a punch and die;

(2) The gripper carriage dwells in advanced position for about 120degrees .of rotation of the flywheel 12 and the fingers 31 remain,ingripping position;

(3) After the flywheel is moved almost 120 beyond top dead center tolower thepunches and just before the punches engage the articles grippedby the fingers 31, the follower roller engages theshoulder 148 to movethe gripping fingers out of the pathof travel of the punches andarticles, the fingers preferably being moved while the gripper carriageis stationary;

(4) As the fiywheel is rotated from about 120 beyond top dead center toabout ,bottom dead center the gripper carriage is ,moved to'fullyretracted position with the gripping fingers out of gripping ,positionand above the dies 5 to 10;

(5) After the flywheel 12 is rotated to about 240 beyond top dead centerand substantially simultaneously with stripping of articles from thepunches by the stripper plate, the follower roller engages the shoulder149 to move the fingers 31 to gripping position, the gripper carriagebeing stationary at this time;

(6) The gripper carriage dwells in its retracted position as theflywheel rotates from about to about 300 beyond top dead center; and

(7) As'the fiywheel 12 rotates about 60 lfrom about 300 beyond top deadcenter'to top dead center, the face groove 75 causes advancing movementof the gripper carriage to the position described in (l) whereby eacharticle is advanced by a pair of gripping fingers 31 from a position inaxial alinement with a punch and die to a position in axial alinementwith an adjacent punch and die.

The above described cycle of operations is repeated for each revolutionof the fiywheel 12, a circular blank being supplied to the die 5 eachtime the punches are retracted and each article formed from a blankbeing advanced automatically in timed relation tov operation of thepunches so that a progressive `series of punching operations areperformed on each article.

It is to be understood that in accordance With the provisions of thepatent statutes, Variations and modifications of the specific devicesherein shown ,and described may be made without departing from thespirit of the invention.

Having described my invention, I claim:

l. A punching machine having a'frame, a row of dies carried by the frameand having a row of equally spaced longitudinally aligned cavities, apunch holder mounted on said frame for movement vertically toward andaway from said dies and carrying a row of aligned equally spaced punchesmovable into and out of said dies to perform a progressive series offorming operations on an article as it is advanced from die to die,means for driving said punch holder to reciprocate said holder and thepunches carried thereby, a dat horizontal stripper plate carried by saidframe having openings therein aligned with said punches, the margins ofsaid openings providing means for separating each article from the punchand die acting thereon during retraction for the punches, reciprocatingmeans for supporting a series of Hat circular blanks and forautomatically feeding a single blank longitudinally forwardly to the dieat one end of said row of dies each time the punches are retracted,means for limiting longitudinal forward movement of said blank beyondsaid die at said one end including a stop member mounted adjacent saiddie for engaging said blank as it moves to said die, means in said diecavities for engaging the articles formed in said dies from said blanksand for ejecting said articles from said die cavities as the punches areretracted, said stripper plate engaging the articles formed during eachpunching operation after the articles are lifted a predetermineddistance above said dies and out of contact with said ejecting means, agripper carriage on said frame, guide members engaging opposite sides ofsaid carriage and permitting longitudinal movement of the carriage in adirection parallel to said rows of punches and die cavities Whilepreventing movement of said carriage in all other directions, equallyspaced pairs of rigid brittle gripping fingers mounted in rows on saidcarriage for movement thereon laterally into and out of anarticle-gripping position between said dies and said strippers, each ofsaid pairs being adapted to engage opposite sides of an article to gripthe same usbstantially as it is stripped from one of said punches andsubstantially until it is engaged by the neXt'adjacent punch, saidgripping fingers being frangible and unable to prevent reciprocation ofsaid carriage, a relatively light-weight actuating member carried bysaid frame and mounted for longitudinal reciprocation parallel to and intimed relation to movement of said carriage, a piston-like carrierrigidly connected to each of said gripping fingers and slidably mountedin a cylinder formed in said carriage for reciprocation in a transversedirection with respect to said carriage, means operably connecting saidcarriage to said punch holder and for reciprocating said carriage intimed relation to reciprocation of said punches to advance each pair ofgripping fingers longitudinally to a first position in lateral alignmentwith one of the punches and thereafter to retract that pair of gripperslongitudinally a distance equal to that between the dies to a secondposition in lateral alignment with the next adjacent punch with a dwellin said first and second positions, yieldable means responsive torelative movement between said gripper carriage and said light-weightactuating member for moving said carriers and the fingers carriedthereby laterally toward and away from the articles above said diesincluding a series of bell crank levers pivotally mounted on saidcarriage and connected between said actuating members and said carriers,each bell crank lever having one lever arm for engaging one of saidcarriers so that the lever imparts a transverse movement to itsassociated carrier that is greater than the relative longitudinalmovement between 18 said actuating member and said carriage to minimizethe change of momentum of the moving parts of the machine, a springbeing interposed between and end of each lever and said actuatingmember, actuating means for automatically moving said actuating memberrelative to said carriage while the carriage dwells at each end of itsstroke including a rotary cam having a body and segments which may beremoved from said body and replaced, said cam being shaped to move thecarriers from Vone end of their stroke to the other while the carriageis stationary at each end of its stroke and while the cam rotatesthrough an angle less than about 10 degrees so that the gripping fingersare moved into and out of their article-gripping positions at maximumspeed, whereby the fingers grip the articles substantiallysimultaneously with stripping of the same from the punches and releasethe articles substantially simultaneously with engagement of the puncheswith the articles, said fingers providing the sole support for saidarticles during the intervals of time wherein said punches are out ofengagement with the articles.

2. A machine as defined in claim 1 wherein the means for reciprocatingsaid gripper carriage comprises a first rotary cam and a first followerengaging said cam and operably connected to said carriage to reciprocatethe same longitudinally and wherein the cam for actuating said actuatingmember is la second rotary cam having a second follower operablyconnected to said actuating member to reciprocate the samelongitudinally parallel to said carriage, said cams being similarlyshaped so that the actuating member and the carriage move substantiallyin unison and having concentric portions of different diameter toprovide a dwell at the end of the stroke of said carri-age, said firstcam being smoothly curved throughout its periphery and said second -camhaving small impact shoulders that impart hammer blows to said secondfollower and cause slight longitudinal movement of the actuating memberrelative to the carriage to move said fingers at high speed into and outof article-gripping positions while the carriage is at each end of itsstroke, each of said impact shoulders having steeply inclined surfacesthat extend less than l0 degrees around the cam.

3. A machine as defined in claim 1 wherein the punches and die `cavitiesare shaped to form from said blanks an annular article having a` radialange, said punches having guide noses of reduced diameter for guidingthe articles into the dies after they are released by said fingers andfor holding the articles concentric to the dies as the articles arestripped from the punches and gripped by said fingers, said fingersmoving a substantial distance laterally while the articles areunsupported so as to clear the radial anges of said articles in aminimum period of time.

References Cited in the tile of this patent UNITED STATES PATENTS625,872 Carbone May 30, 1899 1,497,001 Rotherham lune 10, 1924 1,870,728Hothersall Aug. 9, 1932 1,987,101 Fabrice Ian. 8, 1935 2,012,423 FerrisAug. 27, 1935 2,180,265 Thiel Nov. 14, 1939 2,382,849 Bennett et al.Aug. 14, 1945

